WASHINGTON (Reuters) -The U.S. Commerce Department said on Thursday it has opened a national security investigation into the import of wind turbines and components.

Earlier this week, the department said it was adding wind turbines to a list of products that will face 50% tariffs on the aluminum and steel content. The “Section 232” investigation, which was opened on Aug. 13 but not publicly disclosed previously, could be used as a basis of even higher tariffs on imported wind turbines.

(Reporting by David Shepardson, Editing by Franklin Paul)